autoheading option doesn't work

[k-nishizaki]

I don't need page-level headings, so I specified the -h option or the --autoheading option, but headings are still being generated.

[k-nishizaki]

According to commandlineparser/commandline#290, Commandline.Parser will behave as if the parameter is of type bool and will be true if specified.
However, in wikiexport, the default value of AutoHeader is set to true, and I think that Commandline.Parser cannot change it to false.